Rollover Fish Pass, a strait across Bolivar Peninsula approximately 200 feet wide, 5 feet deep, and more than 1,600 feet long, was opened in 1955 by the Texas Game and Fish Commission to help perpetuate and improve the state's fish and wildlife resources. The pass was constructed to bring enough sea water into East Bay to increase the bay's salinity and to provide additional passage for marine fish traveling to and from spawning and feeding areas. East Bay's lower salinity had resulted from several fresh water streams entering the area from the mainland side of the peninsula, and this excessive fresh water had limited marine fish and restricted the growth of submerged vegetation that provides nursery areas and forms the basis of the food cycle for marine life. The creation of the pass greatly improved salt water fishing conditions in East Bay for the thousands of sportsmen who come there throughout the year. The site had been known as Rollover long before the fish pass was built and was associated with legend from the days of the Spaniards through the American prohibition period. According to legend, the name came from early ship captains who, to avoid the customs station at Galveston, rolled barrels of imported merchandise from the Gulf side of Bolivar Peninsula over to East Bay for transfer to the mainland without further formality, and selected export items were also said to have been moved the same way in reverse.